Geiger counter is a colloquial name for any hand-held radiation measuring device in civil defense, but most civil defense devices were ion-chamber radiological survey meters capable of measuring only
Victoreen Civil Defense V-777-1 shelter radiation detection kit overview
An example of the CD V-715 survey meter.
The Civil Defense CD V-717 with detachable ionization chamber deployed. Ionization chamber portion sits atop yellow anti-contamination bag.
An example of the CD V-720 survey meter, turned upside down, showing the retractable beta shield.
Roentgen (unit)
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The roentgen or röntgen is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by
Display of quartz fiber dosimeter, in units of roentgen.